Unlike the Mac mini, whose virtues are more contentious depending on your view, the iMac - particularly in its 24in guise - is an easier sell. It helps that most alternative 24in all-in-one's are more expensive, largely due to a greater emphasis on multimedia features, but it doesn't change the fact that the iMac is an iconic piece of design that also delivers as a powerful and - lack of Blu-ray excluded - well featured desktop replacement that benefits from one vital and so far unmentioned attribute: Apple OS X.